The present invention relates to a remote control device for various types of electronic apparatuses, and more particularly, to a transmitter for transmitting a remote control signal to an audio-visual system.
An audio-visual system (hereinafter referred to as "A.V. system"), such as a stereo reproduction apparatus, a cassette tape deck, a compact disk player, a television receiver, a video tape deck, and a laser vision disk player, is equipped with a remote control device. The remote control device is a combination of a transmitter and a receiver. The transmitter transmits a remote control signal from a position remote from the A.V. system being controlled. The remote control signal is normally conveyed by infrared rays. The receiver receives the remote control signal transmitted from the transmitter, decodes the control contents and outputs them to the A.V. system.
The transmitter is generally housed in a box-shaped case. On one surface of the case are provided a plurality of key switches from which various operation instructions are input to the transmitter. A display panel such as a liquid crystal panel may also be provided on the same surface of the case. On a surface of the case is provided an infrared radiation emitting element for emitting the remote control signal.
The display panel normally displays images which express functions that a user can control at a certain time, i.e., a menu of key operations, for users' convenience. The display panel may also have the function of confirming that a certain key operation is performed or of displaying the operation being performed at that time.
A display panel of a type which employs a transparent touch panel is also known. Such a display panel has both a display function and a key operation function. This type of display panel has transparent electrodes on the display panel, and allows a user to perform key operations by touching with his or her fingers a predetermined area of the transparent touch panel where a character or symbol representing the contents of the key operation is displayed.
The recent A.V. system trends toward a multi-function A.V. system. There is also a trend toward controlling the entirety of the A.V. system with a single remote control transmitter. In that case, a plurality of functions are allocated to a single key, and the user selects a desired function from these functions. In this way, a large number of functions can be handled without increasing the number of keys to be operated.
However, since a size of the display panel is practically limited, if a large number of operations are simultaneously displayed by the display panel, a display portion for displaying, individual contents becomes small, making a display of menu very difficult to see for the user. In the case of a display panel of the transparent touch panel type, the user has to touch very small areas with his or her fingers. This makes key operation very inconvenient, causing an erroneous touch of adjacent areas.